The Harris CD74HC123, CD74HCT123, CD74HC423 andCD74HCT423 are dual monostable multivibrators withresets. They are all retriggerable and differ only in that the123 types can be triggered by a negative to positive resetpulse; whereas the 423 types do not have this feature. Anexternal resistor (R

X

) and an external capacitor (C

X

) control

the timing and the accuracy for the circuit. Adjustment of Rxand C

X

provides a wide range of output pulse widths from

the Q and Q terminals. Pulse triggering on the A and Binputs occur at a particular voltage level and is not related tothe rise and fall times of the trigger pulses.

Once triggered, the output pulse width may be extended byretriggering inputs A and B. The output pulse can beterminated by a LOW level on the Reset (R) pin. Trailingedge triggering (A) and leading edge triggering (B) inputsare provided for triggering from either edge of the inputpulse. If either Mono is not used each input on the unuseddevice (A, B, and R) must be terminated high or low.

The minimum value of external resistance, Rx is typically 5k

.

The minimum value external capacitance, C

X

, is 0pF. The

calculation for the pulse width is t

W

= 0.45 R

X

C

X

at V

CC

= 5V.

14

15

16

9

13

12

11

10

1

2

3

4

5

7

6

8

1A

1B

1R

1Q

2Q

2C

X

GND

2R

X

C

X

V

CC

1C

X

1Q

2Q

2R

2B

2A

1R

X

C

X

Ordering Information

PART NUMBER

TEMP. RANGE (

o

C)

PACKAGE

PKG.

NO.

CD74HC123E

-55 to 125

16 Ld PDIP

E16.3

CD74HCT123E

-55 to 125

16 Ld PDIP

E16.3

CD74HC423E

-55 to 125

16 Ld PDIP

E16.3

CD74HCT423E

-55 to 125

16 Ld PDIP

E16.3

CD74HC123M

-55 to 125

16 Ld SOIC

M16.15

CD74HCT123M

-55 to 125

16 Ld SOIC

M16.15

CD74HC423M

-55 to 125

16 Ld SOIC

M16.15

CD74HCT423M

-55 to 125

16 Ld SOIC

M16.15

NOTES:

1. When ordering, use the entire part number. Add the suffix 96 to

obtain the variant in the tape and reel.

2. Wafer or die for this part number is available which meets all elec-

CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operationof the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.

NOTE:

3.

JA

is measured with the component mounted on an evaluation PC board in free air.

DC Electrical Specifications

PARAMETER

SYMBOL

TEST

CONDITIONS

V

CC

(V)

25

o

C

-40

o

C TO 85

o

C -55

o

C TO 125

o

C

UNITS

V

I

(V)

I

O

(mA)

MIN

TYP

MAX

MIN

MAX

MIN

MAX

HC TYPES

High Level InputVoltage

V

IH

-

-

2

1.5

-

-

1.5

-

1.5

-

V

4.5

3.15

-

-

3.15

-

3.15

-

V

6

4.2

-

-

4.2

-

4.2

-

V

Low Level InputVoltage

V

IL

-

-

2

-

-

0.5

-

0.5

-

0.5

V

4.5

-

-

1.35

-

1.35

-

1.35

V

6

-

-

1.8

-

1.8

-

1.8

V

High Level OutputVoltageCMOS Loads

V

OH

V

IH

or V

IL

-0.02

2

1.9

-

-

1.9

-

1.9

-

V

-0.02

4.5

4.4

-

-

4.4

-

4.4

-

V

-0.02

6

5.9

-

-

5.9

-

5.9

-

V

High Level OutputVoltageTTL Loads

-

-

-

-

-

-

-

-

-

V

-4

4.5

3.98

-

-

3.84

-

3.7

-

V

-5.2

6

5.48

-

-

5.34

-

5.2

-

V

Low Level OutputVoltageCMOS Loads

V

OL

V

IH

or V

IL

0.02

2

-

-

0.1

-

0.1

-

0.1

V

0.02

4.5

-

-

0.1

-

0.1

-

0.1

V

0.02

6

-

-

0.1

-

0.1

-

0.1

V

Low Level OutputVoltageTTL Loads

-

-

-

-

-

-

-

-

-

V

4

4.5

-

-

0.26

-

0.33

-

0.4

V

5.2

6

-

-

0.26

-

0.33

-

0.4

V

Input LeakageCurrent

I

I

V

CC

or

GND

-

6

-

-

±

0.1

-

±

1

-

±

1

µ

A

Quiescent DeviceCurrent

I

CC

V

CC

or

GND

0

6

-

-

8

-

80

-

160

µ

A

CD74HC123, CD74HCT123, CD74HC423, CD74HCT423

4

HCT TYPES

High Level InputVoltage

V

IH

-

-

4.5 to

5.5

2

-

-

2

-

2

-

V

Low Level InputVoltage

V

IL

-

-

4.5 to

5.5

-

-

0.8

-

0.8

-

0.8

V

High Level OutputVoltageCMOS Loads

V

OH

V

IH

or V

IL

-0.02

4.5

4.4

-

-

4.4

-

4.4

-

V

High Level OutputVoltageTTL Loads

-4

4.5

3.98

-

-

3.84

-

3.7

-

V

Low Level OutputVoltageCMOS Loads

V

OL

V

IH

or V

IL

0.02

4.5

-

-

0.1

-

0.1

-

0.1

V

Low Level OutputVoltageTTL Loads

4

4.5

-

-

0.26

-

0.33

-

0.4

V

Input LeakageCurrent

I

I

V

CC

and

GND

0

5.5

-

±

0.1

-

±

1

-

±

1

µ

A

Quiescent DeviceCurrent

I

CC

V

CC

or

GND

0

5.5

-

-

8

-

80

-

160

µ

A

Additional QuiescentDevice Current PerInput Pin: 1 Unit Load

I

CC

V

CC

-2.1

-

4.5 to

5.5

-

100

360

-

450

-

490

µ

A

NOTE: For dual-supply systems theoretical worst case (V

I

= 2.4V, V

CC

= 5.5V) specification is 1.8mA.

DC Electrical Specifications

(Continued)

PARAMETER

SYMBOL

TEST

CONDITIONS

V

CC

(V)

25

o

C

-40

o

C TO 85

o

C -55

o

C TO 125

o

C

UNITS

V

I

(V)

I

O

(mA)

MIN

TYP

MAX

MIN

MAX

MIN

MAX

HCT Input Loading Table

INPUT

UNIT LOADS

All

0.35

NOTE: Unit Load is

I

CC

limit specified in DC Electrical Table, e.g.

360

µ

A max at 25

o

C.

Prerequisite for Switching Specifications

PARAMETER

SYMBOL V

CC

(V)

25

o

C

-40

o

C TO 85

o

C

-55

o

C TO 125

o

C

UNITS

MIN

TYP

MAX

MIN

TYP

MAX

MIN

TYP

MAX

HC TYPES

Minimum Input,Pulse Width

t

WL

A

2

100

-

-

125

-

-

150

-

-

ns

4.5

20

-

-

25

-

-

30

-

-

ns

6

17

-

-

21

-

-

26

-

-

ns

B

t

WH

2

100

-

-

125

-

-

150

-

-

ns

4.5

20

-

-

25

-

-

30

-

-

ns

6

17

-

-

21

-

-

26

-

-

ns

CD74HC123, CD74HCT123, CD74HC423, CD74HCT423

5

R

t

WL

2

100

-

-

125

-

-

150

-

150

ns

4.5

20

-

-

25

-

-

30

-

30

ns

6

17

-

-

21

-

-

26

-

26

ns

A and B Hold Time

t

H

2

50

-

-

65

-

-

75

-

75

ns

4.5

10

-

-

13

-

-

15

-

15

ns

6

9

-

-

11

-

-

13

-

13

ns

Reset Removal Time

t

REM

2

50

-

-

65

-

-

75

-

75

ns

4.5

10

-

-

13

-

-

15

-

15

ns

6

9

-

-

11

-

-

13

-

13

ns

Retrigger Time Number

t

rT

5

-

-

-

-

-

-

-

-

-

ns

R

X

= 10K

, C

X

= 0

-

50

-

-

63

-

-

76

-

ns

Output Pulse Width

t

W

5

Q or Q

R

X

= 10K

, C

X

= 10nF

40

-

50

38.7

-

51.3

38.2

-

51.8

µ

s

HCT TYPES

Minimum Input,Pulse Width

t

WL

5

-

A

20

-

-

25

-

-

30

-

-

ns

B

t

WH

20

-

-

25

-

-

30

-

-

ns

R

t

WL

20

-

-

25

-

-

30

-

-

ns

A and B Hold Time

t

H

5

10

-

-

13

-

-

15

-

-

ns

Reset Removal Time

t

REM

5

10

-

-

13

-

-

15

-

ns

Retrigger Time Number(Note 4)

R

X

= 10K

, C

X

= 0

t

rT

5

-

50

-

-

63

-

-

76

-

ns

Output Pulse Width Q or Q

t

W

5

40

-

50

38.7

-

51.3

38.2

-

51.8

µ

s

R

X

= 10K

, C

X

= 10nF

NOTE:

4. Time to trigger depends on the values of R

X

and C

X

. The output pulse width can only be extended when the time between the active-

going edges of the trigger input pulses meet the minimum retrigger time requirement.

Prerequisite for Switching Specifications

(Continued)

PARAMETER

SYMBOL V

CC

(V)

25

o

C

-40

o

C TO 85

o

C

-55

o

C TO 125

o

C

UNITS

MIN

TYP

MAX

MIN

TYP

MAX

MIN

TYP

MAX

CD74HC123, CD74HCT123, CD74HC423, CD74HCT423

6

Switching Specifications

C

L

= 50pF, Input t

r

, t

f

= 6ns, R

X

= 10K

, C

X

= 0

PARAMETER

SYMBOL

TEST

CONDITIONS

V

CC

(V)

25

o

C

-40

o

C TO

85

o

C

-55

o

C TO

125

o

C

UNITS

MIN

TYP

MAX

MIN

MAX

MIN

MAX

HC TYPES

Trigger Propagation Delay

t

PHL

C

L

= 50pF

A, B, R to Q

2

-

-

300

-

375

-

450

ns

4.5

-

-

60

-

75

-

90

ns

C

L

= 15pF

5

-

25

-

-

-

-

-

ns

C

L

= 50pF

6

-

-

51

-

64

-

76

ns

A, B, R to Q

t

PHL

C

L

= 50pF

2

-

-

320

-

400

-

480

ns

4.5

-

-

64

-

80

-

96

ns

C

L

= 15pF

5

-

26

-

-

-

-

-

ns

C

L

= 50pF

6

-

-

54

-

68

-

82

ns

Reset Propagation Delay

t

PHL

, t

PLH

C

L

= 50pF

2

-

-

215

-

270

-

325

ns

R to Q or Q

4.5

-

-

43

-

54

-

65

ns

6

-

-

37

-

46

-

55

ns

Output Transition Time

t

THL

, t

TLH

C

L

= 50pF

2

-

-

75

-

95

-

110

ns

4.5

-

-

15

-

19

-

22

ns

6

-

-

13

-

16

-

19

ns

Output Pulse Width

-

-

5

R

X

= 10K

, C

X

= 10pF

-

45

-

-

-

-

-

µ

s

Pulse Width Match BetweenCircuits In the Same Package

-

-

5

R

X

= 10K

, C

X

= 10pF

-

±

2

-

-

-

-

-

%

Power Dissipation Capacitance

C

PD

C

L

= 15pF

5

-

-

-

-

-

-

-

pF

Input Capacitance

C

IN

C

L

= 50pF

-

10

-

10

-

10

-

10

pF

NOTES:

5. C

PD

is used to determine the dynamic power consumption, per multivibrator.